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NPC 인버터 시스템에서 개방성 고장시 PWM 특성을 이용한 새로운 고장 검출 방법
李正大(Jung-Dae Lee),金兌珍(Tae-Jin Kim),河東鉉(Dong-Hyun Ha),玄東石(Dong-Seok Hyun) 대한전기학회 2008 전기학회논문지 Vol.57 No.7
In this paper, a novel fault detection method is proposed when the neutral-point-clamped inverter has a open-circuit fault in the switching device. This proposed method is configured with simple circuit and is achieved by a simple algorithm using the inherent characteristic of the continuous Pulse Width Modulation. Also, this method has the fast fault detection ability and is much simpler to embody, in comparison with conventional fault detection methods. This ability to detect fault minimizes harmful effect which are such as DC-link voltage unbalance and overstress to other switching devices. Therefore, this proposed fault detection method can improve reliability of NPC inverter system. Experimental results are presented to verify the validity of proposed fault detection method.
Risk assessment of triclosan, a cosmetic preservative
Jung Dae Lee(이정대),Joo Young Lee(이주영),Seung Jun Kwack(곽승준),Chan Young Shin(신찬영),Yong-Kyu Choi(최용규),Chung Sik Min(민충식),Hyun Jun Jang(장현준),Hyang Yeon Kim(김향연),Min Kook Kim(김민국),Dong Wan Seo(서동완),Byung-Mu 환경독성보건학회 2019 한국독성학회 심포지움 및 학술발표회 Vol.2019 No.4
BLDC 전동기 운전 특성을 이용한 새로운 고장 검출 기법 구현
이정대(Jung-Dae Lee),박병건(Byoung-Gun Park),김태성(Tae-Sung Kim),류지수(Ji-Su Ryu),현동석(Dong-Seok Hyun) 전력전자학회 2007 전력전자학술대회 논문집 Vol.- No.-
This paper proposes a novel sensorless fault detection algorithm for a brushless DC(BLDC) motor drive system. This proposed method is configured without the additional sensor for fault detection and identification. The fault detection and identification are achieved by a simple algorithm using the operating characteristic of the BLDC motor. This proposed method can also be embedded into existing BLDC motor drive systems as a subroutine without excessive computational effort. The feasibility of a novel sensorless fault detection algorithm is validated in simulation.
차나무(Camellia sinensis)에서 剪枝처리의 强度와 時期가 생육 및 품질에 미치는 영향
이진호(Jin-HO Lee) · 이민석(Min-Seuk Lee) · 이정대(Jung-dae Lee) · 유주(Ju Yoo) · 김영걸(Young-Gul Kim) 한국차학회 2006 한국차학회지 Vol.12 No.2
Pruning is one of the most effective techniques in the tea cultural practice that controls the formation of trunks and branches. In order to find out the suitable intensity and time for pruning, we had tea plants pruned at two different times varying the pruning intensity : tea plants were first pruned at a height of 50cm, 60cm, and 70cm from the surface of the earth respectively on May 30th, 2004, which was 15 days later after the first tea crop, and the second pruning was done at a height of 50cm, 55cm, 60cm, and 65cm from the surface of the earth on July 11th, 2004, 15 days later after the second tea crop. According to the experiment, the more intensive pruning was, the longer bud length and the more opened leaves we could get regardless of the time. It also showed the result that as a pruning position was lowered, the sprouting rate got higher. In addition, the first tea crop showed a lower response to higher pruning intensity, while the yield at the unit area(20cm 20cm) increased except 50cm pruning after the second tea crop. Finally, both the whole and unit area yield turned out to be low when pruned below 50cm after the second tea crop. Therefore, it is considered as a noneffective pruning condition. In conclusion, varying pruning conditions is not recognized to affect on the quality of the first tea crop, because there is no meaningful correlation between chemical component content of tea leaves and different pruning conditions.